JDK-8227870 - Escape Sequences For Line Continuation and White Space (Preview)

[Maurizio Cimadamore]

On 30/09/2019 16:36, Jim Laskey wrote:
> In line.
>
>> On Sep 30, 2019, at 12:29 PM, Maurizio Cimadamore 
>> <maurizio.cimadamore at oracle.com 
>> <mailto:maurizio.cimadamore at oracle.com>> wrote:
>>
>> Hi,
>> in general I see where the enhancements are coming from - but I do 
>> have some comments.
>>
>> One is pedagogical; I think a world where single line strings are 
>> denoted by a single double quote, whereas multi line strings are 
>> denoted by triple double quotes is a relatively wimple world for the 
>> user to grok. This proposal effectively blurs the line between the 
>> two variants, as now you can (in the degenerate case where all lines 
>> in a text block ends with '\') express a single line string with a 
>> text block syntax - which I understand is the part of the goal, but...
>
> And String s = "aa\nbb\ncc\n" is truly single line? I think they are 
> just the same thing wearing different clothes.
I see where you are coming from. While I'm not necessarily opposed, I'd 
be curious to see if this add-on would have repercussions on how the 
text block feature is reasoned about by programmers, especially ones 
coming to Java for the first time.
>
>>
>> The other perplexity is on the use of \s with text blocks; I don't 
>> get why the output in your example ends up being:
>>
>> red<one space><new line>green<one space><new line>blue<one 
>> space><blue line>
>>
>> Why is the space at the left of the '\s' being ignored? In fact, '\s' 
>> is the _only_ thing you can put in that place that will cause the 
>> previous space to be ignored and dropped on the floor, which makes me 
>> uncomfortable. I think that, to get the output you want, '\s' should 
>> be close to the end of red/green/blue - if, on the other hand, if you 
>> add space and _then_ you add a '/s', I don't think we should treat 
>> this differently from adding space and then some _random_ character - 
>> in which case all the space in between will be preserved.
>
> This is a readability issue in the edits. It's actually 
> "red....\ngreen..\nblue...\n". I'll fix.

Phew :-)

Question - can `/s` appear _before_ the end of a line in a text block? 
If so, what happens?

Maurizio

>
>>
>> Maurizio
>>
>>
>> On 30/09/2019 12:45, Jim Laskey wrote:
>>> During the discussion on Text Blocks, several of you stated a need 
>>> for a line continuation construct. I have since created a CSR to 
>>> propose the creation of two new escape sequences: \<line terminator> 
>>> and \s.
>>>
>>> https://bugs.openjdk.java.net/browse/JDK-8227870
>>>
>>>
>>> Please review and comment here.
>>>
>>> Cheers,
>>>
>>> -- Jim
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>
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